1. Field of the Invention
The present invention relates to a retention module for receiving a CPU module, and especially to a retention module including a detachable portion which may be attached to or detached from the retention module for receiving different CPU modules of different size.
2. The Prior Art
A modularized PC board or CPU card has become a trend in the PC industry. Traditionally, the CPU is connected to a mother board either via a connector or direct soldering. However, an advanced manufacturing technique has replaced this by firstly soldering the CPU onto a printed circuit board and then inserting the printed circuit board into a connector mounted on the mother board. Alternatively, the CPU is firstly combined with the PC board as a modularized unit and then inserted into a connector mounted on the mother board. Recently, the modularized CPU unit has become a trend and named "SLOT 1". Normally the modularized CPU unit is connected to a card connector which is further retained by a retention module. The retention module may be classified into vertical, horizontal, or coplanar types.
FIG. 1 illustrates a vertical retention module 61 mounted on a printed circuit board 62 for vertical insertion of a CPU module (not shown). A closure portion 61C is formed at a lower portion of the retention module 61 for receiving a card connector (not shown) which is well known to electrically receive the CPU module. FIG. 2 illustrates a horizontal retention module 63 laterally mounted on a printed circuit board 64 and a card connector 65 fixed in the retention module 63 for electrically receiving a CPU module. A CPU module (not shown) may be inserted into the card connector 65 and retained between two arms of the retention module 63. FIG. 3 illustrates a coplanar retention module 66 having one mating face for receiving an edge of a printed circuit board 67 and another mating surface for receiving a CPU module (not shown). Each type of retention module may receive a specific kind of CPU module, but none of the retention module can accommodate CPU modules of different size.
There are at least two types of popular CPU modules, the Pentium.TM. II SECC.TM. and the Pentium.TM. II Celeron.TM.. The Pentium.TM. II SECC.TM. is rather thick because the related circuit board is enclosed by a plastic housing as designated by numeral 7 in FIG. 6. Also referring to FIG. 7, the Pentium.TM. II Celeron.TM. includes a circuit board 8 and a heat sink 9 attached to a CPU chip of the circuit board 8 thus the combination includes two spaced-apart plates, the circuit board 8 and the heat sink 9, with a CPU chip (not shown) provided therebetween. Since the SECC.TM. CPU module is wider than the Celeron.TM. CPU module and the engaging sides thereof are also different from those of the Celeron.TM. CPU module, a single retention module cannot be used for both. Hence, it is requisite to provide a new retention module which can accommodate both types of CPU modules.